Chair frame



FIG. 1 is a generally perspective view of a chair frame showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a side view thereof the opposite side view being the mirror image thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a top plan view thereof. 

The ornamental design for a "chair frame", as shown and described. 